Light-emitting diode device

ABSTRACT

A light-emitting diode device includes a substrate; a plurality of light-emitting units formed on the substrate, wherein the light-emitting units form a serially-connected array, including n adjacent light-emitting unit rows, wherein n≧5, and the light-emitting units in the same rows connect vertically and/or the light-emitting units in the same columns connect horizontally, and a connecting direction of at least three light-emitting units in two adjacent rows are the same; a plurality of conductive connecting structures connecting the plurality of light-emitting units; a first contact light-emitting unit formed on the substrate and in the first light-emitting unit row; and a second contact light-emitting unit formed on the substrate and in the n th  light-emitting unit row; at least three light-emitting units in the first light-emitting unit row have a 1 st  area, and at least three light-emitting units in the n th  light-emitting unit row have a 2 nd  area, wherein the 1 st  area and the 2 nd  area are not equal.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of TaiwanApplication Serial Number 102142931 filed on Nov. 25, 2013, which isincorporated by reference in its entirety.

BACKGROUND Technical Field

The present disclosure relates to a light-emitting diode device, moreparticularly, to a light-emitting diode array device with high lightextraction.

Description of the Related Art

Lighting principle and structure of the light-emitting diode (LED) aredifferent from the conventional light. The LED has advantages of lowpower consumption, long lifetime, no warm-up time, and fast response.Besides, LED can be very small, has good shock resistance, and issuitable for mass-production so it can easily meet application demandand can be manufactured into a small device or an array device. Theapplications of the LEDs in the market are extensive, such as opticaldisplay device, laser diode, traffic light, data storage device,communication device, lighting device and medical device.

Conventional high voltage light-emitting diode device 1 is shown in FIG.1A and FIG. 1B. The high voltage light-emitting diode device 1 comprisesa transparent substrate 10 and a plurality of light-emitting units 12extending in 2-dimensional direction and closely arranged and formed onthe transparent substrate 10. An epitaxy stack 120 of eachlight-emitting unit 12 comprises a first semiconductor layer 121, anactive layer 122, and a second semiconductor layer 123. Since thetransparent substrate 10 is not conductive, trenches 14 formed betweenthe plurality of epitaxy stacks 120 isolate each light-emitting unit 12.In addition, a portion of the epitaxy stacks 120 of the plurality oflight-emitting units are etched to the first semiconductor layers 121 toform partial exposed areas. Next, conductive connecting structures 19are formed on the second semiconductor layers 123 and the exposed areasof the first semiconductor layers 121 in adjacent light-emitting units.The conductive connecting structure 19 comprises a first electrode 18and a second electrode 16. The first electrode 18 and the secondelectrode 16 comprise a first extending part 180 and a second extendingpart 160 respectively formed on the first semiconductor layer 121 andthe second semiconductor layer 123 of the adjacent light-emitting units.The extending parts help current to uniformly flow into thesemiconductor layers. The plurality of light-emitting units 12 forms anelectric serial circuit or an electric parallel circuit by theconductive connecting structures 19 selectively formed on the firstsemiconductor layer 121 and the second semiconductor layer 123 of theadjacent light-emitting units 12. Under the conductive connectingstructures 19 can be air, and an insulator 13 can also be formed on apart of an upper surface of the epitaxy stack and between the epitaxystacks of the adjacent light-emitting units 12 by CVD or PVD. Theinsulator 13 serves as a protection of the epitaxy stack and anelectrical isolation between the adjacent light-emitting units 12. Thematerial of the insulator 13 is preferably Al₂O₃, SiO₂, AlN, SiN_(x),TiO₂, Ta₂O₅ or combination of the materials described above.

While electrically connecting the light-emitting units 12 by theconductive connecting structures 19, since the elevation difference ofthe trench 14 is large, the conductive connecting structures 19 may bebroken or have poor connection thereby to affect the yield of thedevice.

Besides, the light-emitting diode device 1 can be connected to andcombined with other components to construct a light-emitting device.FIG. 2 shows a conventional art of a light-emitting device. As shown inFIG. 2, the light-emitting device 1 includes a submount 110 comprising acircuit 101 to carry the light-emitting diode device 1 described above,an electrical connection 104 to electrically connect a first electrodepad 16′, a second electrode pad 18′ of the light-emitting diode device 1and the circuit 101 on the submount 110. The submount 110 can be a leadframe or a large mounting substrate to facilitate the design of thecircuit and improve the heat dissipating. The electrical connection 104can be a bonding wire or other connecting structures.

SUMMARY OF THE DISCLOSURE

A light-emitting diode device includes a substrate having a firstsurface; a plurality of light-emitting units formed on the firstsurface, wherein the light-emitting units form a serially-connectedarray, and the array includes a plurality of adjacent light-emittingunit rows and adjacent light-emitting unit columns, wherein thelight-emitting unit row and the light-emitting unit column include atleast three light-emitting units, the light-emitting units in theplurality of adjacent light-emitting unit rows and adjacentlight-emitting unit columns are connected vertically or horizontally; aplurality of conductive connecting structures connecting the pluralityof light-emitting units; and at least three light-emitting units in twoof the adjacent light-emitting unit rows having the same connectingdirection, and the connection of the light-emitting units of one row inat least two adjacent rows and the light emitting units in the adjacentrow comprise one vertical connection and two horizontal connections.

A light-emitting diode device includes a substrate having a firstsurface; a plurality of light-emitting units formed on the firstsurface, wherein the light-emitting units form a serially-connectedarray, and the array comprises n adjacent light-emitting unit rows,wherein n≦5, and the light-emitting units in the same rows connectvertically and/or the light-emitting units in the same columns connecthorizontally, and a connecting direction of at least threelight-emitting units in two adjacent rows are the same; a plurality ofconductive connecting structures connecting the plurality oflight-emitting units; a first contact light-emitting unit formed on thefirst surface and in the first light-emitting unit row, and a firstelectrode pad formed on the first contact light-emitting unit; and asecond contact light-emitting unit formed on the first surface and inthe n^(th) light-emitting unit row, and a second electrode pad formed onthe second contact light-emitting unit; wherein at least threelight-emitting units in the first light-emitting unit row have a firstarea, and at least three light-emitting units in the n^(th)light-emitting unit row have a second area, wherein the first area andthe second area are not equal.

A light-emitting diode device includes a substrate having a firstsurface; a plurality of light-emitting units including four edgesrespectively, formed on the first surface, wherein the light-emittingunits form a serially-connected array, and the array includes at leastthree adjacent rows; and a plurality of conductive connecting structuresconnecting the plurality of light-emitting units, wherein the twoconductive connecting structures of one light-emitting unit are formedon the same edge of the light-emitting unit, and the light-emitting unitwhich has two conductive connecting structures formed on the same edgecrosses two adjacent rows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a cross-sectional view of a conventional light-emittingdiode array device.

FIG. 1B shows a top view of a conventional light-emitting diode arraydevice.

FIG. 2 shows a conventional light-emitting device.

FIG. 3A shows a cross-sectional view of the light-emitting unit inaccordance with one embodiment of present disclosure.

FIGS. 3B˜3G show top views of the light-emitting diode device inaccordance with one embodiment of present disclosure.

FIGS. 4A˜4C show a light-emitting module including the light-emittingdiode device in accordance with another embodiment of presentdisclosure.

FIGS. 5A˜5B show a light source generator including the light-emittingdiode device in accordance with another embodiment of presentdisclosure.

FIG. 6 shows a light bulb including the light-emitting diode device inaccordance with another embodiment of present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present disclosure discloses a light-emitting diode. To better andconcisely explain the disclosure, please refer to the followingdescription and FIG. 3A˜FIG. 6.

Embodiments of the present disclosure will be described in detail withreference to the accompanying drawings. The size of the light-emittingdiode device gradually becomes smaller as the market demand increases.While the area of each light-emitting unit of the LED device becomessmaller, the opaque structures on the light-emitting surface, such asthe electrodes, the electrode extending parts, and the conductiveconnection structures greatly affect the light extraction efficiency ofthe light-emitting units.

FIG. 3A and FIG. 3B show a cross-sectional view and a top view of alight-emitting diode array device 2 in accordance to the firstembodiment of the present disclosure. The light-emitting diode arraydevice 2 comprises a substrate 20 having a first surface 201 and asecond surface 202 opposite to the first surface 201. In thisembodiment, the material of the substrate 20 is sapphire. The substrate20 is not limited to a single material and can be a composite substratecomposed of a plurality of different materials. For example, thesubstrate 20 can comprise a first substrate and a second substrate (notshown) that are bonded with each other. The material of the substrate 20also comprises but is not limited to LiAlO₂, ZnO, GaP, glass, organicpolymer, MN, GaAs, diamond, quartz, Si, SiC or diamond like carbon(DLC).

Next, a plurality of light-emitting units 22 which extends and arrangesin a two-dimensional array is formed on the first surface of thesubstrate 20. The manufacturing method of the light-emitting diode arrayis described as below.

First, an epitaxy stack 220 is formed on a growth substrate (not shown)by conventional epitaxy process. The epitaxy stack 220 comprises a firstsemiconductor layer 221, an active layer 222, and a second semiconductorlayer 223. The material of the growth substrate comprises but is notlimited to GaAs, Ge, InP, sapphire, SiC, silicon, LiAlO₂, ZnO, GaN, orMN. The materials of the semiconductor layer 221, the active layer 222,and the second semiconductor layer 223 include one or more than oneelement selected form Ga, Al, In, As, P, N, Si or the group of thematerials described above.

Then, as shown in FIG. 3B, a portion of the epitaxy stack is selectivelyremoved by a photolithography process to form a plurality of epitaxystacks 220 of the light-emitting units 22 that are separately arrangedon the growth substrate. An exposed region of the first semiconductorlayer 221 of each light-emitting unit 22 can further be formed by thephotolithography process so that the exposed region serves as a platformfor forming conductive connection structures later.

In order to increase light-extraction efficiency of the light-emittingdiode array device, the epitaxy stack 220 of the light-emitting unit canbe disposed on the substrate 20 by substrate transfer and substratebonding. The epitaxy stack 220 of the light-emitting unit can bedirectly bonded with the substrate 20 by heating or pressuring. Theepitaxy stack 220 of the light-emitting unit can also be adhered to thesubstrate 20 by a transparent adhesion layer (not shown). Thetransparent adhesion layer can be organic polymer transparent glue, suchas polyimide, BCB, PFCB, Epoxy, Acrylic resin, PET, PC or combinationthereof; or a transparent conductive oxide metal such as ITO, InO, SnO₂,ZnO, FTO, ATO, CTO, AZO, GZO or combination thereof; or an inorganicinsulator, such as Al₂O₃, SiN_(x), SiO₂, AlN, TiO₂, Ta₂O₅ or combinationthereof.

In fact, the method of forming the epitaxy stack 220 of thelight-emitting unit on the substrate 20 is not limited to theseapproaches. People having ordinary skill in the art can understand thatthe epitaxy stack 220 of the light-emitting unit can be directlyepitaxial grown on the substrate 20 according to differentcharacteristics of the structures. Besides, according to different timesof transferring the substrate 20, the structure with the secondsemiconductor layer 223 near the first surface 201 of the substrate 20,the first semiconductor layer 221 on the second semiconductor layer 223,and the active layer sandwiched therein can be formed.

Next, an insulator 23 is disposed on a part of the surface of theepitaxy stack 220 and between adjacent epitaxy stacks 220 by CVD or PVD,etc. The insulator 23 protects the epitaxy stacks and electricallyinsulates the adjacent light-emitting units. The material of theinsulator is preferably Al₂O₃, SiO₂, AlN, SiN_(x), TiO₂, Ta₂O₅ orcombination of the materials described above.

Then, a plurality of conductive connecting structures 29 which istotally separated with each other is formed on the surfaces of the firstsemiconductor layer 221 and the second semiconductor layer 223 of thetwo adjacent light-emitting units 22 by sputtering. In these totallyseparated conductive connecting structures 29, each of one end of theconductive connecting structure 29 is disposed on the firstsemiconductor layer 221 in single directional arrangement and directlycontacts with the first semiconductor layer 221. The conductiveconnecting structures 29 electrically connect with each other via thefirst semiconductor layer 221. These conductive connecting structuresthat are separated with each other extend to the second semiconductorlayer 223 of another adjacent light-emitting unit 22, and each of theother end electrically connects with the second semiconductor layer 223to electrically connect two adjacent light-emitting units 22 in series.

In fact, the method of electrically connecting adjacent light-emittingunits 22 is not limited to what is described above. People havingordinary skill in the art can understand that two ends of the conductiveconnecting structure are respectively disposed on the semiconductorlayer with same polarity or different polarity of the differentlight-emitting units, so that the light-emitting units 22 can beelectrically connected in series or in parallel.

Referring to the top view in FIG. 3B, in the light-emitting diode device2 which has an electrical series arranged in an array, a first pad 26 isformed on the first semiconductor layer 221 of the first contactlight-emitting unit B1 at the end of the array. In one embodiment, asecond pad 28 can also be formed on the second semiconductor layer 223of the second contact light-emitting unit B2 at the other end of thearray. The light-emitting diode device 2 electrically connects to anexternal power or other circuits by wiring or soldering the first pad 26and the second pad 28. The process of forming the first pad 26 and thesecond pad 28 can be performed in the same process of forming theconductive connecting structures 29. It also can be completed by severalprocesses. The material of the first pad 26 and the second pad 28 can bethe same as or different from that of the conductive connectingstructures 29. In order to achieve a specific conductivity, the materialof the first pad 26, the second pad 28, and the conductive connectingstructures 29 is preferably metal, such as Au, Ag, Cu, Cr, Al, Pt, Ni,Ti, Sn, alloy or stacked composition of the materials described above.

In one embodiment, from the top view in FIG. 3B, the light-emittingunits 22 of the light-emitting diode device 2 are electrically connectedin series and arranged as an array. The light-emitting diode device 2comprises four adjacent light-emitting rows R1-R4 and four adjacentcolumns C1-C4. In this embodiment, the light-emitting units 22 in thefirst light-emitting row R1 vertically connect with each other with astart at the second contact light-emitting unit B2, and horizontallyconnect to the second row and fourth column R2C4 from the first row andfourth column R1C4. Then, the light-emitting units 22 vertically connectin series from the second row and fourth column R2C4 to the second rowand first column R2C1, and next, horizontally connect to the third rowand first column R3C1. As shown in FIG. 3B, between the third and thefourth rows, the light-emitting units 22 alternately connect with thelight-emitting units 22 in the adjacent row in vertical and inhorizontal directions. For example, the third row and first column R3C1horizontally connects to the fourth row and first column R4C1, and thefourth row and first column R4C1 vertically connects to the fourth rowand second column R4C2, Next, the fourth row and second column R4C2horizontally connects to the third row and second column R3C2, and thethird row and second column R3C2 vertically connects to the third rowand third column R3C3. Next, the third row and third column R3C3horizontally connects to the fourth row and third column R4C3, and thefourth row and third column R4C3 vertically connect to the fourth rowand fourth column R4C4. Finally, the fourth row and fourth column R4C4horizontally connects to the third row and fourth column R3C4. The firstpad 26 is formed on the first semiconductor layer 221 of the third rowand fourth column R3C4 to form the first contact light-emitting unit B1.

In this embodiment, the connecting direction of at least threelight-emitting units 22 in the first row is the same as that of at leastthree light-emitting units 22 in the second row. The connectingdirection is vertical in this embodiment. The light-emitting units 22 inthe third row and the fourth row connect with each other alternately invertical and in horizontal so that the first contact light-emitting unitB1 and the second contact light-emitting unit B2 are not disposed on thediagonal of the light-emitting device 2.

FIG. 3C shows a top view in accordance with the second embodiment of thepresent disclosure. In this embodiment, the light-emitting units 22 ofthe light-emitting device 3 electrically connect in series and arrangedas an array. The light-emitting device 3 comprises four adjacentlight-emitting unit rows R1-R4 and four adjacent light-emitting columnsC1-C4. The manufacturing method and the material are the same as that ofthe first embodiment therefore will not be described herein.

In this embodiment, the connecting ways of the first row and the secondrow are the same as the first embodiment, that is, the light-emittingunits 22 in the first light-emitting row R1 vertically connect with eachother with a start at the second contact light-emitting unit B2. Theconnecting direction of at least three light-emitting units 22 in thefirst row is the same as that of at least three light-emitting units 22in the second row. In this embodiment, the connecting direction isvertical.

Different from the first embodiment, in order to form the first contactlight-emitting unit B1 in the fourth row in this embodiment, theelectrical connection of the light-emitting units 22 in the third andthe fourth rows has vertical connections in the third row and thirdcolumn R3C3 and the third row and fourth column R3C4, and the otherlight-emitting units 22 in adjacent rows connect with each other invertical and in horizontal alternately. The first pad 26 is formed onthe first semiconductor layer 221 of the fourth row and third columnR4C3 to form a first contact light-emitting unit B1. The first contactlight-emitting unit B1 and the second contact light-emitting unit B2 arenot disposed on the diagonal of the light-emitting device 3.

FIG. 3D shows a top view of the light-emitting diode device 4 inaccordance with the third embodiment of the present disclosure. In thisembodiment, the light-emitting units 22 of the light-emitting diodedevice 4 electrically connect in series and are arranged as an array.The light-emitting device 4 comprises five adjacent light-emitting unitrows R1-R5. The manufacturing method and the material are the same asthat of the first embodiment therefore will not be described herein.

In this embodiment, the light-emitting units 22 connect with each otherwith a start at the second contact light-emitting unit B2 to the firstcontact light-emitting unit B1. The light-emitting units 22 in eachlight-emitting unit row R1-R5 vertically connect in series, and the lastunit in each light-emitting unit row connects horizontally to theadjacent row. That is, the connecting direction of at least threelight-emitting units 22 in each row is the same as that of at leastthree light-emitting units 22 in the adjacent row. In this embodiment,the connecting direction is vertical.

In this embodiment, each light-emitting unit 22 in the firstlight-emitting unit row R1 which comprises the second contactlight-emitting unit B2 has a first area. Each light-emitting unit 22 inthe second row to the fourth row R2-R4 which comprise light-emittingunits 22 only has a second area. Each light-emitting unit 22 in thefifth light-emitting unit row R5 which comprises the first contactlight-emitting unit B1 has a third area. The first area, the secondarea, and the third area are not equal.

In one embodiment, the difference ratio of any two of the first area,the second area, and the third area is less than 20%. In anotherembodiment, the first light-emitting unit row R1 which comprises thesecond contact light-emitting unit B2 has α light-emitting units. Eachof the second row to the fourth row R2-R4 which comprise light-emittingunits only has β light-emitting units. The fifth light-emitting unit rowR5 which comprises the first contact light-emitting unit B1 has γlight-emitting units. The values of α, β and γ are not equal. In anotherembodiment, the first contact light-emitting unit B1 and the secondcontact light-emitting unit B2 are disposed on the diagonal of thelight-emitting device 4.

FIG. 3E shows a top view of the light-emitting diode device 5 inaccordance with the fourth embodiment, which is also a variation of thefirst embodiment. In this embodiment, the light-emitting units 22 of thelight-emitting diode device 5 electrically connect in series and arearranged as an array. The light-emitting device 5 comprises six adjacentlight-emitting unit rows R1-R6. The manufacturing method and thematerial are the same as that of the first embodiment therefore will notbe described herein.

In this embodiment, the connecting direction of at least threelight-emitting units 22 in any of the first row to the fourth row is thesame. The connecting direction is vertical in this embodiment. Thelight-emitting units 22 in the fifth row and the sixth row connect tothe units in the adjacent rows alternately in vertical and in horizontalso that the first contact light-emitting unit B1 and the second contactlight-emitting unit B2 are not disposed on the diagonal of thelight-emitting device 5.

In this embodiment, the difference from the first embodiment is that thefirst light-emitting unit row R1 which comprises the second contactlight-emitting unit B2 has α light-emitting units 22. Each of the secondrow to the fourth row R2-R4 and the sixth row R6 which compriselight-emitting units only has β light-emitting units 22. The fifthlight-emitting unit row R5 which comprises the first contactlight-emitting unit B1 has γ light-emitting units 22, wherein α≠β=γ.

FIG. 3F shows a top view of the light-emitting diode device 6 inaccordance with the fifth embodiment. In this embodiment, thelight-emitting units 22 of the light-emitting diode device 6electrically connect in series and are arranged as an array. Thelight-emitting device 6 comprises three adjacent light-emitting unitrows R1-R3. The manufacturing method and the material are the same asthat of the first embodiment therefore will not be described herein.

In this embodiment, the connecting direction of at least threelight-emitting units 22 in any of the first row to the third row is thesame. The connecting direction is vertical in this embodiment. In thisembodiment, the last unit in each row vertically connects to the unit inthe adjacent row so that the first contact light-emitting unit B1 andthe second contact light-emitting unit B2 are disposed on the diagonalof the light-emitting diode device 6.

In this embodiment, two conductive connection structures 29 of at leastone light-emitting unit 22 in each row are formed on the same edge ofthe light-emitting unit, and simultaneously connect to two adjacent rowsin vertical. In another embodiment, at least two light-emitting units 22in each row have different area and/or different ratio of the length andthe width.

FIG. 3G shows a top view of the light-emitting diode device 7 inaccordance with the sixth embodiment of the present disclosure. In thisembodiment, the light-emitting units 22 of the light-emitting diodedevice 7 electrically connect in series and are arranged as an array.The light-emitting diode device 7 comprises three adjacentlight-emitting unit rows R1-R3. The manufacturing method and thematerial are the same as that of the first embodiment therefore will notbe described herein.

In this embodiment, at least three light-emitting units 22 in each rowhave a first area, and at least three light-emitting units 22 in thethird row R3 have a second area. The first area and the second area arenot equal.

FIGS. 4A-4C show diagrams of a light-emitting module. FIG. 4A is aperspective view of the light-emitting module. The light-emitting module500 comprises a carrier 502, a light-emitting device (not shown) inaccordance with any embodiment of the present disclosure, a plurality oflenses 504/506/508/510, and two power supply terminals 512/514.

FIGS. 4B˜4C show cross-sectional views of the light-emitting module.FIG. 4C is an enlarged view of a partial area E in FIG. 4B. The carrier502 comprises an upper carrier 503 and a lower carrier 501. A surface ofthe lower carrier 501 contacts with the upper carrier 503 and the lens504 and 508 are formed on the upper carrier 503. A through hole 515 isformed in the upper carrier 503. One of the light-emitting diode devices2, 3, 4, 5 in accordance with the embodiments of present disclosure canbe formed in the through hole 515, contacts with the lower carrier 501,and is covered by a glue 521. The lens 508 is formed on the glue 521.

In one embodiment, a reflector 519 can be formed on two sides of thethrough hole 515 to improve luminous efficiency of the light-emittingmodule 500. A metal layer 517 can be formed on lower surface of thelower carrier 510 to improve heat dissipating efficiency.

FIGS. 5A and 5B show a light source generator 600. The light generator600 comprises a light-emitting module 500, a cover 540, a power suppliersystem (not shown) providing current to the light-emitting module 600,and a controller (not shown) controlling the power supplier system. Thelight source generator 600 can be a lighting device such as street lamp,headlight, or an interior lighting source, and it can also be a trafficlight or a backlight source of a backlight module in a display.

FIG. 6 shows a light bulb. The light bulb 900 comprises a cover 921, alens 922, a lighting module 924, a supporter 924, a heat sink 926, aconnector 927 and an electrical connector 928. The lighting module 924comprises a carrier 923 and one of the light-emitting diode devices 2,3, 4, 5, in accordance with any of the embodiments described above onthe carrier 923.

In one embodiment of the present disclosure, a buffer layer (not shown)can be optionally formed between the first semiconductor layer 221 andthe substrate 20. The buffer layer is between two material systems, andtransits the material system of the substrate 20 to the semiconductormaterial system. For a structure of light-emitting diodes, the bufferlayer reduces lattice-mismatch between two materials. The buffer layercan also serve as combination of two materials or two separatedstructures with single layer or multi-layer. The material of the bufferlayer can be selected form organic material, inorganic material, metalor semiconductor. The structure of the buffer layer can be reflectivelayer, thermal conductive layer, electrical conductive layer, ohmiccontact layer, anti-deformation layer, stress release layer, stressadjustment layer, bonding layer, wavelength conversion layer ormechanical fixing structure, etc.

A contact layer (not shown) is optionally formed on the epitaxy stack220. The contact layer is formed on one side of the epitaxy stack 220opposite to the substrate 20. Specifically, the contact layer is anoptical layer, an electrical layer, or a combination thereof. Theoptical layer can change electromagnetic radiation or light which isgenerated form or enters the active layer 222. The word “change” meanschanging at least one optical characteristic of electromagneticradiation or light, and the optical characteristic comprises but is notlimited to frequency, wavelength, intensity, luminous flux, efficiency,color temperature, rendering index, light field and angle of view. Theelectrical layer can change at least one of the value, density ordistribution of any of voltage, resistance, current, or capacitancebetween other layers and any side of the contact layer. The material ofthe contact layer comprises oxide, conductive oxide, transparent oxide,oxide with more than 50% transparency, metal, relative translucentmetal, metal with more than 50% transparency, organic, inorganic,fluorescent, phosphorescent, ceramic, semiconductor, dopedsemiconductor, undoped semiconductor or any one of the describedmaterials. In some applications, the material of the contact layer isITO, ATO, CTO, ZTO, IZO, AZO or any one of the materials. The thicknessof the relative translucent metal is preferably 0.005 μm˜0.6 μm. In oneembodiment, since the contact layer has a better lateral currentspreading rate, it is helpful for uniform current spreading in theepitaxy stack 220. In general, the bandgap of the contact layer isbetween 0 eV to 5 eV and varies in accordance with different dopant anddifferent process of the contact layer.

It will be apparent to those having ordinary skill in the art thatvarious modifications and variations can be made to the devices inaccordance with the present disclosure without departing from the scopeor spirit of the disclosure. In view of the foregoing, it is intendedthat the present disclosure covers modifications and variations of thisdisclosure provided they fall within the scope of the following claimsand their equivalents.

What is claimed is:
 1. A light-emitting diode device, comprising: asubstrate, comprising a first surface; a plurality of light-emittingunits formed on the first surface, wherein the light-emitting units forma serially-connected array, and the array comprises n adjacentlight-emitting unit rows, wherein n≧5, and the light-emitting units inthe same rows connect vertically and/or the light-emitting units in thesame columns connect horizontally, and a connecting direction of atleast three light-emitting units in two adjacent rows are the same; aplurality of conductive connecting structures connecting the pluralityof light-emitting units; a first contact light-emitting unit formed onthe first surface and in the first light-emitting unit row, and a firstelectrode pad formed on the first contact light-emitting unit; and asecond contact light-emitting unit formed on the first surface and inthe n^(th) light-emitting unit row, and a second electrode pad formed onthe second contact light-emitting unit; wherein at least threelight-emitting units in the first light-emitting unit row have a firstarea, and at least three light-emitting units in the n^(th)light-emitting unit row have a second area, wherein the first area andthe second area are not equal.
 2. The light-emitting diode device ofclaim 1, wherein the light-emitting units in the second light-emittingunit row to the n−1^(th) light-emitting unit row have a third area, andthe third area and the first and/or the second area are not equal. 3.The light-emitting diode device of claim 1, wherein a connection of thelight-emitting units of one light-emitting unit row in at least twoadjacent light-emitting unit rows and the light-emitting units in theadjacent light-emitting unit row comprises one vertical connection andtwo horizontal connection.
 4. The light-emitting diode device of claim1, wherein the deference between the first area and the second area isless than 20%.
 5. The light-emitting diode device of claim 1, whereinthe first light-emitting unit row has α light-emitting units, and then^(th) light-emitting unit row has β light-emitting units, wherein α≠β.6. The light-emitting diode device of claim 1, wherein the substrate isa growth substrate; the first contact light-emitting unit or the secondcontact light-emitting unit comprises: a first semiconductor layer; asecond semiconductor layer formed on the first semiconductor layer; andan active layer formed between the first semiconductor layer and thesecond semiconductor layer.
 7. The light-emitting diode device of claim1, wherein the first contact light-emitting unit and the second contactlight-emitting unit are not formed on a diagonal of the light-emittingdiode device.
 8. The light-emitting diode device of claim 1, wherein thefirst contact light-emitting unit and the second contact light-emittingunit are formed on a first side and a second side opposite to the firstside of the light-emitting diode device respectively.
 9. Thelight-emitting diode device of claim 1, wherein the first contactlight-emitting unit and the second contact light-emitting unit areformed on a first side and a second side adjacent to the first side ofthe light-emitting diode device respectively.